NKG2A educates reconstituting post-HCT NK cells for degranulation but not for cytokine production. CD56⁺CD3⁻–gated NK cells from donor and post-HCT recipient pairs receiving T-cell replete transplants were further gated as KIR⁻NKG2A⁻ (light gray bars), KIR⁻NKG2A⁺ (white bars), KIR⁺NKG2A⁺ (dark gray bars), or KIR⁺NKG2A⁻ (black bars) based on staining with a cocktail of KIR antibodies and NKG2A. CD107a expression and IFNγ production were measured on all 4 subsets after incubation with K562 cells for 4 hours. IFNγ also was measured after overnight stimulation with IL-12 and IL-18. Bars represent the mean ± SEM. Pairwise comparisons were based on a linear mixed model. Statistical significance is indicated as *P < .05, **P < .01, and ***P < .0001. ns = not significant. NE = not evaluable.